Rosetta and Philae – Nomen est omen

Scientists often use abbreviations to designate their missions or projects; examples are MASCOT (Mobile Asteroid Surface Scout) or SHEFEX (Sharp Edged Flight Experiment). But ESA’s Rosetta mission, which will mark a first in the history of space exploration by becoming the first spacecraft to follow a comet and carry a lander that will touch down on the comet, was given its name for a different reason. The name refers to the Rosetta Stone, which allowed hieroglyphs to be deciphered.

In 1799, in the Egyptian city of Rashid (Rosetta), archaeologists discovered a stone with writing on it in two languages (Egyptian and Greek), using three scripts (hieroglyphic, demotic and Greek). In 1822, together with the inscriptions on an obelisk from the Temple of Philae, Jean François Champollion succeeded in deciphering the, until then, totally enigmatic hieroglyphs. With this knowledge, a door was opened for archaeology; the thus far incomprehensible inscriptions were translated, and a bygone civilisation 'rediscovered'.

The Temple of Philae on the Egyptian island of AgilkiaCredit: flickr.com/spinkney (CC BY 2.0)

The European Rosetta mission with the lander Philae has similar aims; it will explore a comet as it awakens during its approach to the Sun. For the first time, a spacecraft will not just fly by a comet, but also follow it along its orbit. Also for the first time, a lander will touch down on a cometand conduct experiments on the surface.

Comets are considered to be witnesses of the birth of the Solar System, which was created by the collapse of a giant, diffuse cloud of gas and dust about 4.6 billion years ago. Previous missions discovered the presence of basic organic molecules in comets; these molecules may have played a role in the origin of life on Earth.

Inscriptions at Philae Temple complex south of the Egyptian city of AswanCredit: flickr.com/isawnyu (CC BY 2.0)

Jagged ice or powdery soil – nobody knows the conditions that the lander will be faced with when it lands on the comet in November 2014. Eleven experiments on the orbiter and ten on the lander will examine the structure and composition of the comet's core and the activity of the comet throughout its journey around the Sun.

The mission target is the comet 67P/Churyumov-Gerasimenko. This name has no hidden meaning and does not represent a mysterious ancient civilisation. Instead, the comet simply bears the name of its discoverers. In 1969, Klim Churyumov Ivanovich , a scientist at the Institute of Astrophysics in Kazakhstan, discovered the celestial body upon examining a photograph that had been exposed for periodic comet 32P/Comas Solá by Svetlana Gerasimenko. At the time, no one could have suspected that the comet would later be the target of a space mission.